[[email protected]]

The current online stereophile has an article of the subjectline.

It addresses sighted audio testing and listening alone testing and the
"quality" of parts used in construction and also the question of what
makes "mid-fi" and "hi-fi".

It is a classic moment in audio of the past 40 years when the entire
question of inherent qualities of gear came to the fore in a dramatic
fashion. It is part of the story as to why many now think that amps are
largely a commodity item chosen for reasons other then inherent high end
majic.

In short Carver said he could make his mid priced solid state amp sound
like any of any amp the stereophile staff chose.

His objective was to test the idea that mega bucks amps with mega buck
innards and finding favor with stereophile as representing "high end"
audio had something inherent that he could not duplicate by making his amp
have the same electrical parameters as the chosen amp. If so the "majic"
something produced by throwing mega bucks at a product was irrelevant.
It would then be all about the parameters and not "high end" majic.

The 4 part article starts he

http://www.stereophile.com/features/...rver_challenge

If you want to jump to the end for the results of the sighted listening
alone tests administered to the stereophile staff:

http://www.stereophile.com/features/...ge/index3.html

Relations between Carver and stereophile were not the best, so the article
should be read in the context discussed in part he

http://en.wikipedia.org/wiki/Bob_Carver

[[email protected]]

On May 27, 7:25*am, wrote:


It is a classic moment in audio of the past 40 years when the entire
question of inherent qualities of gear came to the fore in a dramatic
fashion. *It is part of the story as to why many now think that amps are
largely a commodity item chosen for reasons other then inherent high end
majic.


I don't know what it is you are speaking about in regards to "high end
majic." Is that a new Cirque show in Vegas? But if you are trying to
refer to the age old objectivst/subjectivist debate over the audible
differences between amplifiers this was not any sort of mile stone at
all in that debate. The line had been drawn in the sand way before the
Carver challenge. The Carver challenge did not address that debate in
any way. It was accepted by both Bob Carver and the Stereophile
staffers involved that audible differences between different
amplifiers were real and easily identifiable. That did not change
after the challenge.

[Sonnova]

On Wed, 27 May 2009 10:19:14 -0700, wrote
(in article ):

On May 27, 7:25*am, wrote:


It is a classic moment in audio of the past 40 years when the entire
question of inherent qualities of gear came to the fore in a dramatic
fashion. *It is part of the story as to why many now think that amps are
largely a commodity item chosen for reasons other then inherent high end
majic.


I don't know what it is you are speaking about in regards to "high end
majic." Is that a new Cirque show in Vegas? But if you are trying to
refer to the age old objectivst/subjectivist debate over the audible
differences between amplifiers this was not any sort of mile stone at
all in that debate. The line had been drawn in the sand way before the
Carver challenge. The Carver challenge did not address that debate in
any way. It was accepted by both Bob Carver and the Stereophile
staffers involved that audible differences between different
amplifiers were real and easily identifiable. That did not change
after the challenge.


One thing that the article fails to point out is that not a few of the
assembled staffers couldn't, in any statistically significant way, tell the
difference between the Carver amp and the conrad-johnson tube amp even BEFORE
Carver "nulled" out his inexpensive solid-state amp.

IOW, to many present, there was no significant difference between the sound
of the two amps either before or after Carver modified his amp.

[Ed Seedhouse[_2_]]

On May 27, 12:53*pm, Sonnova wrote:

One thing that the article fails to point out is that not a few of the
assembled staffers couldn't, in any statistically significant way, tell the
difference between the Carver amp and the conrad-johnson tube amp even BEFORE
Carver "nulled" out his inexpensive solid-state amp.
IOW, to many present, there was no significant difference between the sound
of the two amps either before or after Carver modified his amp.

And if I recall right, the adjustments Carver made consisted of
putting a resistor between the output stage and the speakers, thus
increasing the output impedance of his amplifier.

That amplifiers with high output impedances will sound different than
those with low output impedances on many loudspeakers is and was, so
far as I know, not controversial. The frequency response of the high
impedance amplifiers varies when coupled with a typical speaker whose
impedance varies with frequency. So you would expect audible
differences depending of course on the exact values.

[[email protected]]

On Wed, 27 May 2009 10:19:14 -0700, wrote
(in article ):

On May 27, 7:25*am, wrote:
It is a classic moment in audio of the past 40 years when the entire
question of inherent qualities of gear came to the fore in a dramatic
fashion. *It is part of the story as to why many now think that amps are
largely a commodity item chosen for reasons other then inherent high end
majic.


I don't know what it is you are speaking about in regards to "high end
majic." Is that a new Cirque show in Vegas? But if you are trying to
refer to the age old objectivst/subjectivist debate over the audible
differences between amplifiers this was not any sort of mile stone at
all in that debate. The line had been drawn in the sand way before the
Carver challenge. The Carver challenge did not address that debate in
any way. It was accepted by both Bob Carver and the Stereophile
staffers involved that audible differences between different
amplifiers were real and easily identifiable. That did not change
after the challenge.

No, not the sub. vs. obj. thing at all; and it was nothing like a ddebate
in the least.

It was an early example clearly showing that differences in sound are
based on the electrical parameters of an amp independent of anything else.
It hardly requires comment then that two amps with different parameters
might differ enough that they produce a difference in sound.

What changed was to demonstrate that his amp could be made to sound like
their amp by simply matching electrical parameters. There was no other
factor that made a difference inherent in the mega buck amp chosen to
account for its sound or anything else..

This in a day of easy to replicate parameters is the reason that amps are
now a commodity item.

[Sonnova]

On Wed, 27 May 2009 18:36:33 -0700, Ed Seedhouse wrote
(in article ):

On May 27, 12:53*pm, Sonnova wrote:

One thing that the article fails to point out is that not a few of the
assembled staffers couldn't, in any statistically significant way, tell the
difference between the Carver amp and the conrad-johnson tube amp even
BEFORE
Carver "nulled" out his inexpensive solid-state amp.
IOW, to many present, there was no significant difference between the sound
of the two amps either before or after Carver modified his amp.

And if I recall right, the adjustments Carver made consisted of
putting a resistor between the output stage and the speakers, thus
increasing the output impedance of his amplifier.

That amplifiers with high output impedances will sound different than
those with low output impedances on many loudspeakers is and was, so
far as I know, not controversial. The frequency response of the high
impedance amplifiers varies when coupled with a typical speaker whose
impedance varies with frequency. So you would expect audible
differences depending of course on the exact values.



OK. Have to say that I wasn't there. But I had several friends at Stereophile
at the time. They told me that Carver had replaced a number of fixed
resistors in his amplifier circuit with precision potentiometers. He would
measure certain parameters of the conrad-johnson tube amp and then "null-out"
his own amp to give the same readings and when he was finished, no one privy
to the test could tell the difference between the two amps (not that many
could tell before it). It is possible that this was all smoke-and-mirrors and
all he was really doing was inserting a series resistor with the speaker load
which would, as you say, understandably change the sound of the affected
amplifier.

[vlad]

On May 27, 12:53*pm, Sonnova wrote:
. . .
One thing that the article fails to point out is that not a few of the
assembled staffers couldn't, in any statistically significant way, tell the
difference between the Carver amp and the conrad-johnson tube amp even BEFORE
Carver "nulled" out his inexpensive solid-state amp.

IOW, to many present, there was no significant difference between the sound
of the two amps either before or after Carver modified his amp.

Another thing that article filed to point out is their significant
difference in price (more then 12X). If they sound the same, then what
is it that justifies the price of the second one?

vlad

[[email protected]]

On May 28, 7:40*am, wrote:
On Wed, 27 May 2009 10:19:14 -0700, wrote
(in article ):





On May 27, 7:25*am, wrote:
It is a classic moment in audio of the past 40 years when the entire
question of inherent qualities of gear came to the fore in a dramatic
fashion. *It is part of the story as to why many now think that amps are
largely a commodity item chosen for reasons other then inherent high end
majic.

I don't know what it is you are speaking about in regards to "high end
majic." Is that a new Cirque show in Vegas? *But if you are trying to
refer to the age old objectivst/subjectivist debate over the audible
differences between amplifiers this was not any sort of mile stone at
all in that debate. The line had been drawn in the sand way before the
Carver challenge. The Carver challenge did not address that debate in
any way. It was accepted by both Bob Carver and the Stereophile
staffers involved that audible differences between different
amplifiers were real and easily identifiable. That did not change
after the challenge.

No, not the sub. vs. obj. thing at all; and it was nothing like a ddebate
in the least.

It was an early example clearly showing that differences in sound are
based on the electrical parameters of an amp independent of anything else. *
It hardly requires comment then that two amps with different parameters
might differ enough that they produce a difference in sound.



Not sure that the obvious ever needed such a demonstration. I don't
know of very many people who believe that the sound of an amp is a
result of anything but it's electrical parameters. If there is a
debate it would be which electrical parameters affect the sound and to
what degree they affect the sound.




What changed was to demonstrate that his amp could be made to sound like
their amp by simply matching electrical parameters. *There was no other
factor that made a difference inherent in the mega buck amp chosen to
account for its sound or anything else..


Well then nothing really changed. No one involved in that test ever
asserted that amps with matching output signals would not sound the
same.




This in a day of easy to replicate parameters is the reason that amps are
now a commodity item




It would seem that it was not so easy for Bob Carver in that day. It
may be that we need a modern version of that test to show just how
easy it is to do the same today.

[Sonnova]

On Thu, 28 May 2009 07:41:33 -0700, vlad wrote
(in article ):

On May 27, 12:53*pm, Sonnova wrote:
. . .
One thing that the article fails to point out is that not a few of the
assembled staffers couldn't, in any statistically significant way, tell the
difference between the Carver amp and the conrad-johnson tube amp even
BEFORE
Carver "nulled" out his inexpensive solid-state amp.

IOW, to many present, there was no significant difference between the sound
of the two amps either before or after Carver modified his amp.

Another thing that article filed to point out is their significant
difference in price (more then 12X). If they sound the same, then what
is it that justifies the price of the second one?

vlad

Ask yourself this: If there is no difference in sound between a pair of $10
Radio Shack interconnects and a $4000 pair of Nordost Valhalla interconnects
(and statistically speaking, there isn't), what justifies spending 400X as
much for the Nordost?

It has to come down to what African-Americans call "Bling". The old Carver
"Cube" was, if memory serves, a very unprepossessing looking bit of kit.
While the conrad-johnson amp was big, heavy, resplendent in it's gold and
black livery with big, glowing tubes and huge transformers. It must be
similar to why people are willing to spend so much money on, essentially,
nothing when they buy expensive cables. It's big-boy jewelry.

Lets face it, many audiophiles buy as much with their wallets and eyes as
they do with their ears. Add that to the amount of audio mythology that's out
there for the technically ignorant to get snagged upon, and there is plenty
of room for the unscrupulous (or perhaps the terribly self deluded) to feed
upon the unwary.

Great case in point. I have two beautiful VTL 140 monoblock power amps for
which I paid more than $6000 for about 15 years ago. They each use SIX
pre-war (WWII, for you youngsters) designed 807 transmitter tubes. They have
huge computer style filter capacitors and big transformers with chromed
end-bells. They look great and sound excellent. But I also have a $200
Behringer model A500 solid state power amplifier.

http://www.behringer.com/EN/Products/A500.aspx

Designed to be rack mounted, this amp produces about 160 Watts/channel into 8
Ohms (and can be bridged for 500 Watts at 8-Ohms mono). It has XLR balanced,
quarter-inch phone balanced or unbalanced as well as unbalanced RCA inputs,
5-way binding posts for speakers, individual level controls for right/left
channels and a multi-segment LED power meter on the front with clip and
overload protection indicators!

It sounds so good, so clean and is so un-fussy that I power my Martin-Logan
Vistas with it instead of with my VTLs. The Vista is a 4-Ohm system and the
Behringer amp is spec'd at 250 Watts/channel into 4-Ohms . It powers them
magnificently. In a true ABX test that I was party to last year, a group of
six audiophiles couldn't statistically tell the difference between my $200
Behringer and a $9000 Audio Research HD220 power amp (Check google, my post
about how the tests were conducted, and the full results might still be
available).

The Behringer amp is in use day in and day out, never gets hot, is ultra
reliable and sounds great. There is simply no reason to buy anything more.
Sure, they look very plain and "studio" business-like with their charcoal
gray cabinets and contrasting light-gray plastic fascia piece, and there is
no chrome - no "bling" but they deliver the goods. Need more power? Buy two
of them and flip the bridging switches on the back, Now you have 500 very
clean Watts/channel for which you have paid only $400 or less than one dollar
per Watt! Who says that high-end audio needs to cost an arm and a leg?

[mcdonaldREMOVE TO ACTUALLY REACH [email protected]]

Sonnova wrote:

OK. Have to say that I wasn't there. But I had several friends at Stereophile
at the time. They told me that Carver had replaced a number of fixed
resistors in his amplifier circuit with precision potentiometers. He would
measure certain parameters of the conrad-johnson tube amp and then "null-out"
his own amp to give the same readings and when he was finished, no one privy
to the test could tell the difference between the two amps (not that many
could tell before it). It is possible that this was all smoke-and-mirrors and
all he was really doing was inserting a series resistor with the speaker load
which would, as you say, understandably change the sound of the affected
amplifier.


Not smoke and mirrors. There are other things to change as well.
First among these (second after the series output resistor) is
to put a capacitor in parallel with it, or between its output and
ground. This changes the high frequency response and damping.
Next is changing the high frequency feedback and frequency
response of the amp, e.g. the high frequency cutoff frequency and phase response.
This is, as I have pointed out before, vitally important at high
levels since high frequencies, even ultrasonic ones, can become
easily audible at low frequencies due to intermodulation distortion in speakers.

Doug McDonald

[Robert Peirce[_2_]]

In article ,
Sonnova wrote:

Ask yourself this: If there is no difference in sound between a pair of $10
Radio Shack interconnects and a $4000 pair of Nordost Valhalla interconnects
(and statistically speaking, there isn't), what justifies spending 400X as
much for the Nordost?

Actually, there probably is some difference, but which is better and
does it matter?

The two cables almost certainly have some electrical difference, perhaps
quite small. A sufficiently long run might allow you to hear the
difference.

You might find the RS cable sounds better, or not. Then you have to
weigh the cost. If the Nordost cable does sound better, is it 400X
better? I find it hard to believe that it might be, but I have not
tried the exercise.

--
Robert B. Peirce, Venetia, PA 724-941-6883
bob AT peirce-family.com [Mac]
rbp AT cooksonpeirce.com [Office]

[Sonnova]

On Fri, 29 May 2009 21:48:23 -0700, Robert Peirce wrote
(in article ):

In article ,
Sonnova wrote:

Ask yourself this: If there is no difference in sound between a pair of $10
Radio Shack interconnects and a $4000 pair of Nordost Valhalla
interconnects
(and statistically speaking, there isn't), what justifies spending 400X as
much for the Nordost?

Actually, there probably is some difference, but which is better and
does it matter?

There cannot be. Period. If there is, it's because the Nordost has been
designed to act as a filter, introducing high amounts of resistance,
capacitive and inductive reactance to the cable - which means it's altering
the frequency response of the signal passing through it in some way. This is
NOT desirable, even if it is what these expensive cables are designed to do
(which I doubt). Please understand this. Wire is wire. Over a meter or so,
there is NOTHING a plain piece of shielded wire, made from a reasonably good
conducting material, could possibly do to an audio signal no matter how small
(like from a moving coil cartridge) or large (between a pre-amp and a power
amp. for instance where the line-level signal might swing plus or minus 10
volts or more)!

Some audio cable makers, and indeed some audiophiles, like to make the case
that perhaps there are aspects of conductor design that physics hasn't yet
addressed. Many cable manufacturers have come-up with elaborate "scientific"
explanations on their websites having to do with inter-conductor capacitance
and strand twist and all kinds of mumbo-jumbo to justify their extravagant
pricing. This is grasping at straws, whistling in the dark, and wishful
thinking. At audio frequencies (say, between DC and about 50 KHz) none of
these things can have any effect whatsoever on the signal.

The two cables almost certainly have some electrical difference, perhaps
quite small. A sufficiently long run might allow you to hear the
difference.

Sure. If you run a cable that has around 100pF/meter of capacitance for 20
meters or so, you might be able to measure a rolloff in frequency response of
perhaps a dB or so at 20 KHz (I haven't done the math but that's only 2000
pF. Using the equation for capacitive reactance:

Xc = 1/2pfC

Whe

Xc = capacitive reactance in ohms
p = pi (3.14)
f = the frequency in Hertz
C = the capacitance in Farads

You can figure the correct impedance at 20 Khz and 2000 pf. I'm not going to
bother because I can tell you that it's negligible.


You might find the RS cable sounds better, or not.

No double-blind test ever made (to my knowledge) has found any expensive
cable identifiable in any audible way from a cheap cable that is routinely
supplied with some components like CD players or tuners.

Then you have to
weigh the cost. If the Nordost cable does sound better, is it 400X
better? I find it hard to believe that it might be, but I have not
tried the exercise.

It's not just hard to believe, it's electrically impossible for there to be
any difference whatsoever - especially in a 1 or 2 meter length.

Now, I'll grant you that the Nordost is much better made than the Radio Shack
cable, is quasi-balanced (good for low interference and avoiding ground
loops) and probably looks great with woven carbon fiber jacket, substantial
gold plated connectors and is probably as big around as your thumb, but,
that's just bling. None of it helps the electrons get from one component to
another in any way shape of form.

[Robert Peirce[_2_]]

In article ,
Sonnova wrote:

There cannot be. Period. If there is, it's because the Nordost has been
designed to act as a filter, introducing high amounts of resistance,
capacitive and inductive reactance to the cable - which means it's altering
the frequency response of the signal passing through it in some way. This is
NOT desirable, even if it is what these expensive cables are designed to do
(which I doubt). Please understand this. Wire is wire. Over a meter or so,
there is NOTHING a plain piece of shielded wire, made from a reasonably good
conducting material, could possibly do to an audio signal no matter how small
(like from a moving coil cartridge) or large (between a pre-amp and a power
amp. for instance where the line-level signal might swing plus or minus 10
volts or more)!

Oh, I thought we were talking about cable, a braided or twisted bunch of
individual wires. I agree on a single wire. However, in your second
sentence, you point out why two cables could sound different.

Whether it is desirable or not really depends on how it changes the
electrical characteristics of the audio chain. That may be why some
combinations of audio chains sound better, worse or different from
others. Positive errors in one part of the chain could offset negative
errors in another part. If you know that is happening, it actually
could be desirable. It is no different than room equalizers that listen
to a test signal and make adjustments to the output of a speaker.

Of course, if the electrical characteristics of two cables were
identical, I would be surprised if anybody could hear a difference with
any consistency. It would run counter to anything I ever learned.

--
Robert B. Peirce, Venetia, PA 724-941-6883
bob AT peirce-family.com [Mac]
rbp AT cooksonpeirce.com [Office]

[Sonnova]

On Mon, 1 Jun 2009 20:57:18 -0700, Robert Peirce wrote
(in article ):

In article ,
Sonnova wrote:

There cannot be. Period. If there is, it's because the Nordost has been
designed to act as a filter, introducing high amounts of resistance,
capacitive and inductive reactance to the cable - which means it's altering
the frequency response of the signal passing through it in some way. This
is
NOT desirable, even if it is what these expensive cables are designed to do
(which I doubt). Please understand this. Wire is wire. Over a meter or so,
there is NOTHING a plain piece of shielded wire, made from a reasonably
good
conducting material, could possibly do to an audio signal no matter how
small
(like from a moving coil cartridge) or large (between a pre-amp and a power
amp. for instance where the line-level signal might swing plus or minus 10
volts or more)!

Oh, I thought we were talking about cable, a braided or twisted bunch of
individual wires. I agree on a single wire. However, in your second
sentence, you point out why two cables could sound different.

Not really. There is no way (that I know of) to "build" enough inductance or
capacitance into a 1 or 2 meter shielded length of cable to act as a filter
at audio frequencies without adding huge resistance which would attenuate the
signal and make THAT cable not as loud as the competition. No cable
manufacturer would want that.

Whether it is desirable or not really depends on how it changes the
electrical characteristics of the audio chain.

It can do one of three things: attenuate the signal equally over the entire
audio spectrum, or, roll-off (parallel resonance) or peak (series resonance)
the extreme high end. And without capacitance, resistance and possibly
inductance values far larger than could be done playing with wire strands,
twists and dielectrics in a piece of cable, the frequencies affected would
all be above 15 KHz.

That may be why some
combinations of audio chains sound better, worse or different from
others. Positive errors in one part of the chain could offset negative
errors in another part.

Your fundamental premise assumes that there can be anything done without
external passive or active components that could affect the audio bandpass in
any way shape or form. Electrical theory says no.

If you know that is happening, it actually
could be desirable. It is no different than room equalizers that listen
to a test signal and make adjustments to the output of a speaker.

Again, you assign "tone-control" attributes to cable that simply cannot be
done with lengths of coax and a couple of RCA connectors.

Of course, if the electrical characteristics of two cables were
identical, I would be surprised if anybody could hear a difference with
any consistency. It would run counter to anything I ever learned.

The problem is that the electrical characteristics of any two equal lengths
of coax cannot be different enough to effect any audible difference between
them. Scores (and possibly hundreds) of ABX and double-blind tests back this
up. No group of listeners has ever been able to statistically establish that
any two interconnect cables sound different. In such tests, no one has ever
been able to tell which cable that they were hearing with any confidence
level above that of blind chance. I'm not surprised, the electronics says
that this is exactly the result that one should get.

[Robert Peirce[_2_]]

In article ,
Sonnova wrote:

I think I disagree with you much less than you think I do. I have not
practiced my trade in many years so I could not today say what level of
resistance, capacitonce or induction would actually produce something
that could be heard in a meter length of cable. I don't even remember
the equations to calculate it. However, I don't believe any real world
cable one meter long would sound any different from another meter length
of cable

What I said was two long enough pieces of cable, and I can't even guess
how long, would sound different if their electrical characteristics were
different. Even a slight difference in resistance would cause one cable
to attenuate the sound more than the other, if the cables were long
enough.

--
Robert B. Peirce, Venetia, PA 724-941-6883
bob AT peirce-family.com [Mac]
rbp AT cooksonpeirce.com [Office]

[Sonnova]

On Tue, 2 Jun 2009 21:42:10 -0700, Robert Peirce wrote
(in article ):

In article ,
Sonnova wrote:

I think I disagree with you much less than you think I do. I have not
practiced my trade in many years so I could not today say what level of
resistance, capacitonce or induction would actually produce something
that could be heard in a meter length of cable. I don't even remember
the equations to calculate it. However, I don't believe any real world
cable one meter long would sound any different from another meter length
of cable

What I said was two long enough pieces of cable, and I can't even guess
how long, would sound different if their electrical characteristics were
different. Even a slight difference in resistance would cause one cable
to attenuate the sound more than the other, if the cables were long
enough.



Sure, take two 20 meter long (about 60 ft) pieces of coax that each have
different capacitance and resistances and inductances per meter, and their
filtering effect might just intrude into the audible spectrum and might make
the cables pass the frequencies above the corner frequency of the filter
formed by the cable in very different ways. This would, at some point, become
audible. Unfortunately for the cable industry, this will not happen at any
length that any audiophile is likely to use in his/her system.